The effects of wind on scintillation decorrelation times are well known only for winds transverse to the propagation path. Therefore, we have investigated such effects using laser scintillation and sonic anemometer data obtained at an outdoor test site at DRDC-Valcartier. The data were taken during both day and night periods in May and June 2003. Meteorological data were also taken over these periods. Scintillation decorrelation times were then compared with the times deduced using the sonic anemometer wind data and Clifford's theory, which only uses the wind component transverse to the propagation path of the laser. Substantial differences were observed, because Clifford's theory does not take into account the effects of the wind's longitudinal component. A simple theoretical model has been developed to include the longitudinal wind. The model includes a free parameter that must be fitted to the data. Once this is done, the model allows us to predict, with reasonable accuracy, the scintillation decorrelation time scale given the inner scale and the wind at any angle. Residual discrepancies may be due to the internal evolution of the turbulence, which has not been included in our model and causes a decorrelation independent of the wind.